The Mycosis Fungoides Cooperative Group was founded in order to study both the natural history of and various treatment regimens for mycosis fungoides in all stages of the disease. To date, 400 cases of pathologically documented mycosis fungoides have been accrued and follow-up information is current on more than 95% of these patients. All data have been computerized and are in the process of being examined to seek correlations with various demographic, history and physical examination, laboratory and pathologic data. Two randomized studies are also in progress and have accrued 80 patients - one study involves patch testing of cutaneous disease and the other involves chemotherapy of visceral disease. The Baltimore Cancer Research Program has entered four patients onto the latter study. Two patients failed therapy, one patient died from bleomycin pulmonary toxicity, and one patient cleared her peripheral blood of Sezary cells but did not clear her skin. Of the 400 study patients who are being followed, but are not on chemotherapy protocols from the study group, there have been 14 from the BCRP and 9 patients continue to be followed by the BCRP. There are no firm conclusions yet from this study.